Objectives: 1. To produce and characterize a series of methacrylate ester gels of controlled water content, controlled fixed positive charge, and controlled fixed negative charge. 2. To determine the interfacial properties of such gels at the gel/aqueous solution interface. To study the biological properties of such gels, with emphasis on blood-interactions, particularly platelets and plasma proteins. 4. To prepare gel coatings and grafts with optimial blood compatibility properties. Bibliographic references: J. D. Adrade, ed., Hydrogels for Medical and Related Applications, Amer. Chem. Soc. Symposium Series, to be publ. early 1976. Papers preprinted in Polymer Preprints, 16 (2), August, 1975. The following papers in the book acknowledge support by this grant: M.S.Jhon, A.M. Ma, S. Hattori, D.E. Gregoris, J.D. Andrade, "Role of Water in the Osmotic and Viscoelastic Behavior of Gel Networks".